Facebook workers routinely suppressed news stories of interest to conservative readers from the social network’s influential “trending” news section, according to a former journalist who worked on the project. This individual says that workers prevented stories about the right-wing CPAC gathering, Mitt Romney, Rand Paul, and other conservative topics from appearing in the highly-influential section, even though they were organically trending among the site’s users.

Several former Facebook “news curators,” as they were known internally, also told Gizmodo that they were instructed to artificially “inject” selected stories into the trending news module, even if they weren’t popular enough to warrant inclusion—or in some cases weren’t trending at all. The former curators, all of whom worked as contractors, also said they were directed not to include news about Facebook itself in the trending module.

In other words, Facebook’s news section operates like a traditional newsroom, reflecting the biases of its workers and the institutional imperatives of the corporation. Imposing human editorial values onto the lists of topics an algorithm spits out is by no means a bad thing—but it is in stark contrast to the company’s claims that the trending module simply lists “topics that have recently become popular on Facebook.”

These new allegations emerged after Gizmodo last week revealed details about the inner workings of Facebook’s trending news team—a small group of young journalists, primarily educated at Ivy League or private East Coast universities, who curate the “trending” module on the upper-right-hand corner of the site. As we reported last week, curators have access to a ranked list of trending topics surfaced by Facebook’s algorithm, which prioritizes the stories that should be shown to Facebook users in the trending section. The curators write headlines and summaries of each topic, and include links to news sites. The section, which launched in 2014, constitutes some of the most powerful real estate on the internet and helps dictate what news Facebook’s users—167 million in the US alone—are reading at any given moment.